REGRESSION EQUATIONS WITH A TI-83/84 CALCULATOR

1) Turn STAT PLOTS ON – necessary if entering statistical data to see a scatterplot

- 2ND then Y=

- Choose 1:PLOT 1

- Move cursor over ON then ENTER

- Move down so

TYPE is highlighting scatterplot(first choice)

XLIST press 2ND and 1 for 𝐿1

YLIST press 2nd and 2 for 𝐿2

MARK – your choice

COLOR – your choice

2) To clear old data

- STAT and 1: EDIT

- Move cursor over 𝐿1 and CLEAR, ENTER

- Move cursor over 𝐿2 and CLEAR, ENTER

3) To enter data

- Once you’ve cleared old data, move cursor under 𝐿1 and enter all x values in your data

- Move to 𝐿2 to enter all y values

4) To see scatterplot

- ZOOM and 9:ZOOMSTAT

5) To calculate the line/curve of best fit

- STAT – move cursor across to CALC

- Choose correct regression type, for example 4:LINREG if linear equation or 5:QUADREG if

quadratic equation

- Make sure XLIST is 𝐿1 and YLIST is 𝐿2

- Move down to calculate and ENTER

6) To copy and paste equation to see line/curve of best fit over the scatterplot

- Y= - VARS - 5:STATISTICS - Move over to EQ - 1:RegEQ

- GRAPH to see scatterplot and line/curve of best fit

7) To use line/curve of best fit to interpolate or extrapolate for x or y values

a) To find missing y value when given x

GRAPH, 2ND and TRACE, 1:VALUE and enter your x value and ENTER b) To find missing x value when given y

Y= to enter another equation with your y value, GRAPH, 2ND and TRACE 5:INTERSECT to find point of intersection of line/curve of best fit and your y

value and ENTER three times to see corresponding value to your y value

***Remember to turn OFF STAT PLOTS if you are given an equation that you want to graph***